// DHTML3API.js custom API for cross-platform
// object positioning by Danny Goodman (http://www.dannyg.com).
// Release 3.0. Supports NN4, IE, and W3C DOMs.
var DHTMLAPI = {
	browserClass: new Object(),
	init: function ()
	{
		this.browserClass.isCSS = ((document.body && document.body.style) ? true : false);
		this.browserClass.isW3C = ((this.browserClass.isCSS && document.getElementById) ?
true : false),
this.browserClass.isIE4 = ((this.browserClass.isCSS && document.all) ?
true : false),
this.browserClass.isNN4 = ((document.layers) ? true : false),
this.browserClass.isIECSSCompat = ((document.compatMode &&
document.compatMode.indexOf("CSS1") >= 0) ? true : false)
	},
	// Seek nested NN4 layer from string name
	seekLayer: function (doc, name)
	{
		var elem;
		for (var i = 0; i < doc.layers.length; i++)
		{
			if (doc.layers[i].name == name)
			{
				elem = doc.layers[i];
				break;
			}
			// dive into nested layers if necessary
			if (doc.layers[i].document.layers.length > 0)
			{
				elem = this.seekLayer(doc.layers[i].document, name);
				if (elem) { break; }
			}
		}
		return elem;
	},
	// Convert element name string or object reference
	// into a valid element object reference
	getRawObject: function (elemRef)
	{
		var elem;
		if (typeof elemRef == "string")
		{
			if (this.browserClass.isW3C)
			{
				elem = document.getElementById(elemRef);
			} else if (this.browserClass.isIE4)
			{
				elem = document.all(elemRef);
			} else if (this.browserClass.isNN4)
			{
				elem = this.seekLayer(document, elemRef);
			}
		} else
		{
			// pass through object reference
			elem = elemRef;
		}
		return elem;
	},
	// Convert element name string or object reference
	// into a valid style (or NN4 layer) object reference
	getStyleObject: function (elemRef)
	{
		var elem = this.getRawObject(elemRef);
		if (elem && this.browserClass.isCSS)
		{
			elem = elem.style;
		}
		return elem;
	},
	// Position an element at a specific pixel coordinate
	moveTo: function (elemRef, x, y)
	{
		var elem = this.getStyleObject(elemRef);
		if (elem)
		{
			if (this.browserClass.isCSS)
			{
				// equalize incorrect numeric value type
				var units = (typeof elem.left == "string") ? "px" : 0;
				elem.left = x + units;
				elem.top = y + units;
			} else if (this.browserClass.isNN4)
			{
				elem.moveTo(x, y);
			}
		}
	},
	// Move an element by x and/or y pixels
	moveBy: function (elemRef, deltaX, deltaY)
	{
		var elem = this.getStyleObject(elemRef);
		if (elem)
		{
			if (this.browserClass.isCSS)
			{
				// equalize incorrect numeric value type
				var units = (typeof elem.left == "string") ? "px" : 0;
				if (!isNaN(this.getElementLeft(elemRef)))
				{
					elem.left = this.getElementLeft(elemRef) + deltaX + units;
					elem.top = this.getElementTop(elemRef) + deltaY + units;
				}
			} else if (this.browserClass.isNN4)
			{
				elem.moveBy(deltaX, deltaY);
			}
		}
	},
	// Set the z-order of an object
	setZIndex: function (obj, zOrder)
	{
		var elem = this.getStyleObject(obj);
		if (elem)
		{
			elem.zIndex = zOrder;
		}
	},
	// Set the background color of an object
	setBGColor: function (obj, color)
	{
		var elem = this.getStyleObject(obj);
		if (elem)
		{
			if (this.browserClass.isCSS)
			{
				elem.backgroundColor = color;
			} else if (this.browserClass.isNN4)
			{
				elem.bgColor = color;
			}
		}
	},
	// Set the visibility of an object to visible
	show: function (obj)
	{
		var elem = this.getStyleObject(obj);
		if (elem)
		{
			elem.visibility = "visible";
		}
	},
	// Set the visibility of an object to hidden
	hide: function (obj)
	{
		var elem = this.getStyleObject(obj);
		if (elem)
		{
			elem.visibility = "hidden";
		}
	},
	// return computed value for an element's style property
	getComputedStyle: function (elemRef, CSSStyleProp)
	{
		var elem = this.getRawObject(elemRef);
		var styleValue, camel;
		if (elem)
		{
			if (document.defaultView && document.defaultView.getComputedStyle)
			{
				// W3C DOM version
				var compStyle = document.defaultView.getComputedStyle(elem, "");
				styleValue = compStyle.getPropertyValue(CSSStyleProp);
			} else if (elem.currentStyle)
			{
				// make IE style property camelCase name from CSS version
				var IEStyleProp = CSSStyleProp;
				var re = /-\D/;
				while (re.test(IEStyleProp))
				{
					camel = IEStyleProp.match(re)[0].charAt(1).toUpperCase();
					IEStyleProp = IEStyleProp.replace(re, camel);
				}
				styleValue = elem.currentStyle[IEStyleProp];
			}
		}
		return (styleValue) ? styleValue : null;
	},
	// Retrieve the x coordinate of a positionable object
	getElementLeft: function (elemRef)
	{
		var elem = this.getRawObject(elemRef);
		var result = null;
		if (this.browserClass.isCSS || this.browserClass.isW3C)
		{
			result = parseInt(this.getComputedStyle(elem, "left"));
		} else if (this.browserClass.isNN4)
		{
			result = elem.left;
		}
		return result;
	},
	// Retrieve the y coordinate of a positionable object
	getElementTop: function (elemRef)
	{
		var elem = this.getRawObject(elemRef);
		var result = null;
		if (this.browserClass.isCSS || this.browserClass.isW3C)
		{
			result = parseInt(this.getComputedStyle(elem, "top"));
		} else if (this.browserClass.isNN4)
		{
			result = elem.top;
		}
		return result;
	},
	// Retrieve the rendered width of an element
	getWidth: function (elem)
	{
		var result = null;
		if (elem)
		{
			if (elem.offsetWidth)
			{
				if (elem.scrollWidth && (elem.offsetWidth != elem.scrollWidth))
				{
					result = elem.scrollWidth;
				} else
				{
					result = elem.offsetWidth;
				}
			} else if (elem.clip && elem.clip.width)
			{
				// Netscape 4 positioned elements
				result = elem.clip.width;
			}
		}
		return result;
	},
	// Retrieve the rendered height of an element
	getHeight: function (elem)
	{
		var result = null;
		if (elem)
		{
			if (elem.offsetHeight)
			{
				result = elem.offsetHeight;
			} else if (elem.clip && elem.clip.height)
			{
				result = elem.clip.height;
			}
		}
		return result;
	},
	// Retrieve the rendered width of an element
	getElementWidth: function (elemRef)
	{
		var result = null;
		var elem = this.getRawObject(elemRef);
		if (elem)
		{
			if (elem.offsetWidth)
			{
				if (elem.scrollWidth && (elem.offsetWidth != elem.scrollWidth))
				{
					result = elem.scrollWidth;
				} else
				{
					result = elem.offsetWidth;
				}
			} else if (elem.clip && elem.clip.width)
			{
				// Netscape 4 positioned elements
				result = elem.clip.width;
			}
		}
		return result;
	},
	// Retrieve the rendered height of an element
	getElementHeight: function (elemRef)
	{
		var result = null;
		var elem = this.getRawObject(elemRef);
		if (elem)
		{
			if (elem.offsetHeight)
			{
				result = elem.offsetHeight;
			} else if (elem.clip && elem.clip.height)
			{
				result = elem.clip.height;
			}
		}
		return result;
	},
	// Return the available content width space in browser window
	getInsideWindowWidth: function ()
	{
		if (window.innerWidth)
		{
			return window.innerWidth;
		} else if (this.browserClass.isIECSSCompat)
		{
			// measure the html element's clientWidth
			return document.body.parentElement.clientWidth;
		} else if (document.body && document.body.clientWidth)
		{
			return document.body.clientWidth;
		}
		return null;
	},
	// Return the available content height space in browser window
	getInsideWindowHeight: function ()
	{
		if (window.innerHeight)
		{
			return window.innerHeight;
		} else
		{
			if (document.body.clientHeight != document.body.parentNode.clientHeight)
			{
				// measure the html element's clientHeight
				return document.body.parentNode.clientHeight;
			} else
			{
				return document.body.clientHeight;
			}
		}
		return null;
	}
}